“Rare Books” are defined as those parts of the Library collection that fit one or more of the following categories:

1) Volumes printed before 1850 in the Americas, and before 1775 in Europe and the other continents (these thresholds of rarity will be periodically advanced).

2) Items including a unique autograph or other unique manuscript elements (marginalia, annotations, etc.). Note that not all books signed by an author or illustrator are necessarily “rare”. Discretion is used in evaluating signed copies. The following criteria are considered:

a. The book itself (or all of the authors’ writings) is of special interest.

b. The book is an association copy, containing a signature, bookplate, or other evidence of ownership by a distinguished person, especially if the book itself or its owner is closely tied to the Museum.

3) Signed presentation copies of books written by a member of the Museum staff (whether on a subject of interest to the Museum or not).

4) Books known to be very scarce or known to be of especially high monetary value.

5) Original bindings of types which are extremely scarce, or which may be associated with known early binders and their shops, or with a particular owner and in general, books with unique or highly distinctive formats.

6) Books less than four inches in height.

7) Volumes with unique graphic elements such as hand-colored plates, significant maps or graphics and portfolios of unbound hand colored prints.

8) Classic or “landmark” books in the field, preferably in their first or definitive editions and subsequent revisions issued under the direct auspices of the author (for example, Darwin’s On the Origin of Species and its various editions) -- modern editions are thus normally excluded; also, first English editions of works originally published in other languages.

9) Limited editions (issued in editions of fewer than 200 copies).

10) Selected curiosa, (as, for example, Edgar Alan Poe’s plagiarized volume on conchology).